title: Purification and measurement of calpromotin, the cytoplasmic protein which activates calcium-dependent potassium transport.
abstract: A simple procedure is described for the purification of calpromotin, a protein from the cytoplasm of red blood cells which is capable of activating calcium-dependent potassium transport. The purification steps involve a salt gradient elution from an anion exchange column (Whatman DE-52) followed by a potassium phosphate gradient elution from a column of hydroxyapatite (HA Ultrogel). These steps result in a 54% yield with a 161 fold purification. The calpromotin is estimated to be 99% pure as determined by densitometry of the protein profile on an SDS polyacrylamide gel. A competitive enzyme-linked immunosorbent assay (ELISA) using rabbit anti-human calpromotin antibodies, is described for measuring levels of calpromotin in the 5 to 100 ng range.
authors.affiliation: Department of Pediatrics, University of South Alabama, Mobile 36617.
authors.forename: R B
authors.initials: RB
authors.lastname: Moore
authors.forename: G A
authors.initials: GA
authors.lastname: Plishker
authors.forename: S K
authors.initials: SK
authors.lastname: Shriver
mesh_terms: D001693:Biological Transport, Active; D001798:Blood Proteins / Q000032:analysis / Q000302:isolation & purification*; D002352:Carrier Proteins; D002848:Chromatography, DEAE-Cellulose / Q000379:methods; D002850:Chromatography, Gel / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D008970:Molecular Weight; D011188:Potassium / Q000097:blood*; D012016:Reference Values
chemical_list: D001798:Blood Proteins; D002352:Carrier Proteins; D011188:Potassium